1. Field of the Invention
The present invention provides a sensor for a media feed path. More specifically, the present invention provides a sensor which detects a type of media in a feed path and further detects when a jam-door is open.
2. Description of the Related Art
It has been previously suggested to utilize an L-path media feed system for stand-alone printers and multi-functions devices. In L-path media feed systems, the input media is positioned at the rear of the device in a nearly vertical orientation. The L-path media feed system further comprises a substantially horizontal output tray and a printing zone defined between the input tray and the output tray. The media is moved through a feed path from the near vertical orientation to a substantially horizontal orientation. Thus when viewed from a side, the media moves through a substantially L-shaped path.
However, L-path paper feeds have several shortcomings. First, L-path paper feed devices have a large height dimension because of the input tray extending upwardly from the peripheral to support input media. Thus, placement of the device on a shelf or cabinet may be difficult. In addition, paper loading may also be problematic when the unit is placed within the shelf or cabinet because the media generally extends above the input tray. Second, the media extends above the input tray and is visible to those around the machine, which is generally not aesthetically pleasing to many users. Finally, L-path paper feeds are prone to multi-sheet feed problems because of the orientation of the input media. More specifically, the input media is continuously forced downward into a pick area by gravity due to the nearly vertical orientation of the media. As a result of the continuous force on the input media, friction bucklers are utilized to inhibit movement of more than one sheet of media from the input tray to a feed area. However, the friction bucklers may mark and/or bend the media in addition to being an added expense to manufacturers and consumer. These problems in combination have led some to a change from utilization of an L-path media feed system to a C-path media feed system.
In general, C-path media feed systems overcome these problems. A C-path paper feed utilizes a substantially horizontally disposed input tray adjacent a substantially horizontally disposed output tray. Typically, the input tray is positioned beneath the output tray and, as such, is also known as a bottom loading device. The feed path is generally curved from the input tray to the output tray in order to move the media through a print zone and from a side resembles a substantially C-shaped path. Due to the construction of the C-path media feed, the height of the peripheral or printer is decreased. In other words, the device lacks the large upwardly extending media tray. Further, the media is generally hidden from view within the interior of the printer or multi-function device. Finally, with the input tray oriented horizontally, the C-path feed device does not have the multi-sheet feed gravity effects typically associated with L-path media feeds. Consequently, multi-feeds are less likely to occur and friction bucklers are not required. Along the C-path device is a media sensor to sense the type of media being moved through the device.
Since implementing the C-path media feed, an additional unforeseen problem has developed. C-path media path devices must include a means for clearing a media jams within the peripheral device. Typically, a jam-door is positioned in the rear portion of the printer or peripheral to provide access to the feed path and a means for clearing the media jam. However when such a jam-door is opened, media will not feed properly for printing. Further, a user may be exposed to moving parts such as gears and rollers in the area of the jam-door. In order to overcome such a problem, an additional electrical circuit has been used to notify a print processor that the jam-door is disposed in an open condition. However, an additional circuit adds complexity and cost to such printing devices and further may result in additional opportunity for product malfunction, all of which are undesirable.
Given the foregoing deficiencies, it will be appreciated that an apparatus is needed which senses media as well as sensing when the jam-door is open and inhibiting operation of a printer or printer portion of a multi-function peripheral when a jam-door is opened so that media will not incorrectly feed and further so that users will not be exposed to moving parts during such an attempted operation.